PROJECT SUMMARY/ABSTRACT Of the nearly 4 million live births each year in the United States, approximately 560,000, or 14% of these women will develop depression within the first four months postpartum. The consequences are substantial: diminished quality of life and significant emotional suffering for women. PPD predicts diminished mother?infant bonding and poor outcomes in social?emotional and, for some, cognitive development. Relying on standard pharmacologic and psychological interventions, PPD is undertreated in part because women are reluctant to seek treatment due to the stigma associated with mental health care, logistical barriers to attending added health care appointments, and disinclination to take medications while breastfeeding. Risk factors for PPD are relatively well delineated. Even though prenatal depressive symptoms are some of the most reliable predictors, evidenced?based, preventive interventions for PPD are rare. Of the preventative interventions, few leverage the unique dyadic orientation of the childbearing period or imbed services in obstetrical care. To address the huge knowledge gap in the prevention and treatment of PPD, we developed (R21MH092665?01) and tested in a preliminary randomized control trial (RCT) a new intervention called PREPP (Practical Resources for Effective Postpartum Parenting) and, following promising published data, we propose to conduct a larger RCT of this treatment. PREPP enrolls pregnant women at risk for PPD, spans late pregnancy to the 6? week postpartum check up. It consists of four in?person `coaching' sessions adjunctive to obstetrical (OB) prenatal and postnatal appointments, and one phone session. PREPP includes (a) mindfulness and self? reflection skills, (b) parenting skills and (c) psycho?education. For this proposed project, we have three study aims to be realized in a PREPP vs Enhanced Treatment as Usual RCT of 214, 3rd trimester pregnant women (ages 18?35) at risk for PPD assessed 2x in pregnancy and at 6, 12, and 16 weeks postpartum: (1) Reduce women's distress during pregnancy (2) Determine the maintenance of improved maternal mood and differences in infant behavior (3) Identify some of the pathways by which PREPP positively affects the mother? infant dyad. PREPP is innovative in its novel conceptualization of PPD and design to overcome barriers to PPD treatment. The traditional clinical approach to PPD has as a focus the individual and improving their symptoms. In PREPP, PPD is viewed as a potential disorder of the mother?infant dyad, which can be approached through preventive psychological and behavioral changes in the mother ? commencing before birth ? that affect her and the child. PREPP exemplifies the vanguard of health care innovations aiming to increase metal health care uptake by integrating behavioral health services with primary health care. The proposed research is significant because it is expected to advance the treatment and prevention of PPD, and generate new knowledge about mother?infant behav-ioral influences during the first months of postnatal life.